The brothers also opened up about their mother for the first time on the 20th anniversary of Princess Diana's death, in an unprecedentedly candid interview about what she was like as a parent.

Four-year-old Prince George started at London's prestigious Thomas's Battersea and it was announced his younger sister, Princess Charlotte — who turned two this year — would be starting at Willocks Nursery in January.

(Getty)

Image: Getty

Both also joined their parents on the royal tour of Germany and Poland.